chore: Merge pull request #738 from charliejmoore/cycle-sort-tests

Cycle sort tests

Sorts/CycleSort.js

@@ -8,8 +8,13 @@
  * Wikipedia: https://en.wikipedia.org/wiki/Cycle_sort
  */
 
+/**
+ * cycleSort takes an input array of numbers and returns the array sorted in increasing order.
+ *
+ * @param {number[]} list An array of numbers to be sorted.
+ * @return {number[]} An array of numbers sorted in increasing order.
+ */
 function cycleSort (list) {
-  let writes = 0
   for (let cycleStart = 0; cycleStart < list.length; cycleStart++) {
     let value = list[cycleStart]
     let position = cycleStart
@@ -20,11 +25,10 @@ function cycleSort (list) {
         position++
       }
     }
-    // if its the same continue
+    // if it is the same, continue
     if (position === cycleStart) {
       continue
     }
-
     while (value === list[position]) {
       position++
     }
@@ -32,7 +36,6 @@ function cycleSort (list) {
     const oldValue = list[position]
     list[position] = value
     value = oldValue
-    writes++
 
     // rotate the rest
     while (position !== cycleStart) {
@@ -48,20 +51,9 @@ function cycleSort (list) {
       const oldValueCycle = list[position]
       list[position] = value
       value = oldValueCycle
-      writes++
     }
   }
-  return writes
+  return list
 }
 
-/**
-* Implementation of Cycle Sort
-*/
-const array = [5, 6, 7, 8, 1, 2, 12, 14]
-// Before Sort
-console.log('\n- Before Sort | Implementation of Cycle Sort -')
-console.log(array)
-// After Sort
-console.log('- After Sort | Implementation of Cycle Sort -')
-console.log(cycleSort(array))
-console.log('\n')
+export { cycleSort }

Sorts/test/CycleSort.test.js

@@ -0,0 +1,69 @@
+import { cycleSort } from '../CycleSort'
+
+describe('cycleSort function', () => {
+  it('should correctly sort an input list that is sorted backwards', () => {
+    const array = [5, 4, 3, 2, 1]
+    expect(cycleSort(array)).toEqual([1, 2, 3, 4, 5])
+  })
+
+  it('should correctly sort an input list that is unsorted', () => {
+    const array = [15, 24, 3, 2224, 1]
+    expect(cycleSort(array)).toEqual([1, 3, 15, 24, 2224])
+  })
+
+  describe('Variations of input array lengths', () => {
+    it('should return an empty list with the input list is an empty list', () => {
+      expect(cycleSort([])).toEqual([])
+    })
+
+    it('should correctly sort an input list of length 1', () => {
+      expect(cycleSort([100])).toEqual([100])
+    })
+
+    it('should correctly sort an input list of an odd length', () => {
+      expect(cycleSort([101, -10, 321])).toEqual([-10, 101, 321])
+    })
+
+    it('should correctly sort an input list of an even length', () => {
+      expect(cycleSort([40, 42, 56, 45, 12, 3])).toEqual([3, 12, 40, 42, 45, 56])
+    })
+  })
+
+  describe('Variations of input array elements', () => {
+    it('should correctly sort an input list that contains only positive numbers', () => {
+      expect(cycleSort([50, 33, 11, 2])).toEqual([2, 11, 33, 50])
+    })
+
+    it('should correctly sort an input list that contains only negative numbers', () => {
+      expect(cycleSort([-1, -21, -2, -35])).toEqual([-35, -21, -2, -1])
+    })
+
+    it('should correctly sort an input list that contains only a mix of positive and negative numbers', () => {
+      expect(cycleSort([-40, 42, 56, -45, 12, -3])).toEqual([-45, -40, -3, 12, 42, 56])
+    })
+
+    it('should correctly sort an input list that contains only whole numbers', () => {
+      expect(cycleSort([11, 3, 12, 4, -15])).toEqual([-15, 3, 4, 11, 12])
+    })
+
+    it('should correctly sort an input list that contains only decimal numbers', () => {
+      expect(cycleSort([1.0, 1.42, 2.56, 33.45, 13.12, 2.3])).toEqual([1.0, 1.42, 2.3, 2.56, 13.12, 33.45])
+    })
+
+    it('should correctly sort an input list that contains only a mix of whole and decimal', () => {
+      expect(cycleSort([32.40, 12.42, 56, 45, 12, 3])).toEqual([3, 12, 12.42, 32.40, 45, 56])
+    })
+
+    it('should correctly sort an input list that contains only fractional numbers', () => {
+      expect(cycleSort([0.98, 0.4259, 0.56, -0.456, -0.12, 0.322])).toEqual([-0.456, -0.12, 0.322, 0.4259, 0.56, 0.98])
+    })
+
+    it('should correctly sort an input list that contains only a mix of whole, decimal, and fractional', () => {
+      expect(cycleSort([-40, -0.222, 5.6, -4.5, 12, 0.333])).toEqual([-40, -4.5, -0.222, 0.333, 5.6, 12])
+    })
+
+    it('should correctly sort an input list that contains duplicates', () => {
+      expect(cycleSort([4, 3, 4, 2, 1, 2])).toEqual([1, 2, 2, 3, 4, 4])
+    })
+  })
+})